BUG-23451 Allow setting date in string index for Series

Author: JustinZhengBC

pandas/core/series.py

@@ -947,6 +947,9 @@ def _set_with(self, key, value):
                 except Exception:
                     pass
 
+            if isinstance(key, str):
+                key = [key]
+
             if not isinstance(key, (list, Series, np.ndarray, Series)):
                 try:
                     key = list(key)

pandas/tests/series/test_datetime_values.py

@@ -548,3 +548,9 @@ def test_minmax_nat_series(self, nat):
     def test_minmax_nat_dataframe(self, nat):
         assert nat.min()[0] is pd.NaT
         assert nat.max()[0] is pd.NaT
+
+    def test_set_dt_with_string_index(self):
+        from datetime import date
+        x = pd.Series([1, 2, 3], index=['Date', 'b', 'other'])
+        x.Date = date.today()
+        assert x.Date == date.today()